Have Historical Climate Changes Affected Gentoo Penguin (Pygoscelis papua) Populations in Antarctica? New Paper

 Authors:

• Fabiola Peña M.,
• Elie Poulin,
• Gisele P. M. Dantas,
• Daniel González-Acuña,
• Maria Virginia Petry,
• Juliana A. Vianna 
  
  

• Published: April 23, 2014
• DOI: 10.1371/journal.pone.0095375

Abstract

The West Antarctic Peninsula (WAP) has been suffering an increase in its atmospheric temperature during the last 50 years, mainly associated with global warming. This increment of temperature trend associated with changes in sea-ice dynamics has an impact on organisms, affecting their phenology, physiology and distribution range. For instance, rapid demographic changes in Pygoscelis penguins have been reported over the last 50 years in WAP, resulting in population expansion of sub-Antarctic Gentoo penguin (P. papua) and retreat of Antarctic Adelie penguin (P. adeliae). Current global warming has been mainly associated with human activities; however these climate trends are framed in a historical context of climate changes, particularly during the Pleistocene, characterized by an alternation between glacial and interglacial periods. During the last maximal glacial (LGM~21,000 BP) the ice sheet cover reached its maximum extension on the West Antarctic Peninsula (WAP), causing local extinction of Antarctic taxa, migration to lower latitudes and/or survival in glacial refugia. We studied the HRVI of mtDNA and the nuclear intron βfibint7 of 150 individuals of the WAP to understand the demographic history and population structure of P. papua. We found high genetic diversity, reduced population genetic structure and a signature of population expansion estimated around 13,000 BP, much before the first paleocolony fossil records (~1,100 BP). Our results suggest that the species may have survived in peri-Antarctic refugia such as South Georgia and North Sandwich islands and recolonized the Antarctic Peninsula and South Shetland Islands after the ice sheet retreat.

Click this link to download the full paper

Satellite CCTV to scrutinize penguins’ breeding habits

23 April 2014

By Tereza Pultarova

Penguin populations in Antarctica are constantly monitored via satellite-connected cameras [Credit: Alasdair Davies]

•  

Three high-tech satellite-connected cameras have been installed near the South Pole in a unique attempt to monitor penguin populations battling climate change.

The camera system, designed by Cambridge Consultants, has previously been deployed to study wild-life in Kenya and will now be put to test in harsh Antarctic conditions.

“We have installed the system in January on a small island near the South Pole,” said Jonathan Pallant, a senior engineer at Cambridge Consultants. “It consists of three cameras communicating wirelessly with a hub unit, using a custom-developed protocol.”

The motion activated cameras transmit images in real time via the Iridium satellite constellation to UK-based zoologists, enabling them to see what the animals are doing even if they are thousands of miles away. The cameras use infra-red LED flash lighting which allows them to capture images night and day.

  Satellite-based penguin monitoring enables researchers to uncover how the species reacts to the climate change [Credit: Alasdair]

Most of the technology used is identical with that employed last year to monitor rhinos in Kenya, including a Raspberry Pi computer at the centre of the system. However, Antarctica places extra demand on battery design and durability.

“We considered a whole range of environments when designing the system, starting with African deserts and savannahs, to extremely moist and cold environments,” Pallant said. “Of course the system needs to be watertight to protect the electronics. However, the biggest challenge is the battery. We used a car battery as it performs the best in extremely cold conditions.”

As the Antarctic winter is approaching the reliability of the battery system would be critical as the cameras’ solar panels won’t generate any electricity.

So far, zoologists studying penguins have had to rely on data gathered during their challenging missions to Antarctica. The penguin-focused CCTV will thus help keep an eye on the animals all year round, providing better understanding of how these animals cope with the progressing climate change.

  The unobtrusive cameras rely on car batteries to survive Antarctic winter and a Raspberry Pi computer to communicate with

“The unique thing about this system is the fact that we can change the configuration of the system remotely using the Iridium satellites,” said Marion Campbell, practice director at Cambridge Consultants. “We don’t need to be there physically, in order to, for example, adjust the timing delay between the trigger and the moment when the actual picture is taken.”

The trial, part of the Penguin Lifeline project, is a cooperation between Cambridge Consultants, Oxford University and the Zoological Society of London. As the results have been promising, the team plans to deploy additional cameras in selected areas across Antarctica in the coming months, ahead of the penguin breeding season.

source

Gut capacity limits bird's ability to adapt to rapid climate change

Date:

April 15, 2014

Source:

University of Rhode Island

Summary:

An ornithologist has found that the capacity of a bird’s gut to change with environmental conditions is a primary limiting factor in their ability to adapt to the rapidly changing climate. And he believes that most other animals are also limited in a similar way.

---

Sparrow. An ornithologist who studies the physiological changes that birds undergo to migrate has found that the capacity of a bird's gut to change with environmental conditions is a primary limiting factor in their ability to adapt to the rapidly changing climate. And he believes that most other animals are also limited in a similar way. Credit: © chas53 / Fotolia

                                                                         ~~~~~

An ornithologist at the University of Rhode Island who studies the physiological changes that birds undergo to migrate has found that the capacity of a bird's gut to change with environmental conditions is a primary limiting factor in their ability to adapt to the rapidly changing climate. And he believes that most other animals are also limited in a similar way.

Scott McWilliams, URI professor of natural resources science, says that spare capacity -- the extent to which animals can modify their physiology to deal with ecological changes -- varies from species to species, with some having great capacity to change while others do not. "It's all about the time scale over which evolution occurs in relation to the timing of the changes now occurring in the environment, because there are likely to be mismatches," he said. "Our rapid climate change is happening too quickly for most animals to evolve a response." His research, funded by the National Science Foundation, was published last week in The Proceedings of the Royal Society.

McWilliams and a colleague at the University of Wisconsin measured the spare capacity of white-throated sparrows, a common migratory songbird in eastern North America. He found that birds acclimated to a very cold environment (-29C) were able to eat 2 to 4 times as much food as sparrows acclimated to summer temperatures, although the sparrows could not eat enough to live at temperatures colder than -29C. "They dramatically increase the size of their gut to accommodate the greater amount of food they must eat to meet their energy needs in the cold, yet they are able to just as efficiently digest their food when they eat much more," said McWilliams. "That tells us something about their ability to flexibly respond to climate change. Plenty of birds migrate south because they have too limited a capacity to respond in this way. But white-throated sparrows have the spare capacity to modify their physiology to deal with substantial environmental change."

However, when the birds were given no time to acclimate to the cold temperatures, they were only able to increase their food intake by about 50 percent. The researchers found that the birds needed at least two days to acclimate to the new conditions before they were able to eat more.

One implication of this finding is that birds that fly long distances in migration -- an activity that causes their gut size to decrease because they do not eat while flying -- need a day or two to reconstitute their gut before they can resume the maximum food intake required to continue their migration.

McWilliams says that his study has defined the ultimate limits of the gut capacity of white-throated sparrows. If similar limits could be established for other species, that data could be incorporated into climate models to better understand which species will likely be able to survive the coming environmental changes. "All organisms have some level of spare capacity," McWilliams said. "The animals that live in constant environments haven't had to evolve much capacity, so those animals are probably going to have the greatest challenge adapting to changing conditions."

According to the researchers, the limits of spare capacity have been studied in very few other species, with most work focused on several varieties of snakes. But they say that the limitations all animals face are in their ability to convert food into usable energy. "The gut limits the overall design of the animal," McWilliams said.

The URI researcher's next step is to do similar studies of how the fat composition of birds changes with environmental conditions and in response to their energy needs. Since certain polyunsaturated fats are known to improve flight performance, McWilliams said that this study will have relevance to the type of food birds should strive to eat in preparation for migration and thus what type of foods should be provided to birds in the landscape.

---

Story Source:
The above story is based on materials provided by University of Rhode Island. Note: Materials may be edited for content and length.

---

Journal Reference:

1. S. R. McWilliams, W. H. Karasov. Spare capacity and phenotypic flexibility in the digestive system of a migratory bird: defining the limits of animal design. Proceedings of the Royal Society B: Biological Sciences, 2014; 281 (1783): 20140308 DOI: 10.1098/rspb.2014.0308

---

University of Rhode Island. "Gut capacity limits bird's ability to adapt to rapid climate change." ScienceDaily. ScienceDaily, 15 April 2014. <www.sciencedaily.com/releases/2014/04/140415133819.htm>.